‘Net Zero’ school become money-maker for Warren County

January 14, 2013

Richardsville Elementary generates more energy than it uses, which resulted in the Tennessee Valley Authority sending the school district a check for $37,227. Photo by Tom Eblen

 

The numbers are in, and America’s most energy-efficient school building has performed even better than expected.

I wrote about Richardsville Elementary near Bowling Green in August 2010 as it was nearing completion. The 77,466-square-foot school was designed to be “net-zero,” meaning it would generate as much energy each year as it used.

Warren County has been a national leader in energy-efficient schools, with each new building outperforming the last. This rural, 550-student school was to be the star — the nation’s most energy-efficient school.

Most of the school’s energy savings come from advanced design and materials, which are not much more expensive than conventional construction. But the key to net-zero was a $2.7 million solar-panel system to generate electricity. On cloudy days, the school can draw power from the Tennessee Valley Authority grid. On sunny days, the excess power generated feeds into TVA’s system.

Plans called for the solar-panel system to pay for itself within 14 years. But the payback will be quicker because performance has exceeded expectations, said the architect, Kenny Stanfield of Sherman Carter Barnhart in Louisville.

In the first full year of operation, the school generated 10 percent more electricity than it used, and TVA sent the school district a check for $37,227.

“So not only does the school not have a utility bill, but it’s a positive revenue stream,” Stanfield said.

Unfortunately, other state utilities don’t pay cash, only offering credits, for excess power generation.

That is likely to change as utility economics make it more attractive to buy electricity from small producers than build costly power plants.

Since Richardsville opened, Sherman Carter Barnhart has built four more Kentucky schools that are “net-zero ready,” meaning all they need is solar-panel generation systems. Two are in Warren County; the others are in Meade and Anderson counties. Two more are being designed, for Bardstown and Taylorsville.

Solar-panel prices continue to fall every year, making school power generation more attractive. Stanfield said they now cost about half what they did when the Richardsville project was bid.

Fayette County’s first venture into this arena is Locust Trace AgriScience Farm. Architect Susan Hill of Lexington firm Tate Hill Jacobs says April-October data showed the school’s solar systems generated more power than the school used, but the key test will be how it performs during the cloudy, winter months.

Fayette County Public Schools recently announced long-term construction plans. Energy-efficient technology will be a big part of those new buildings, spokeswoman Lisa Deffendall said, but it is too early to know specifics. The district also has an aggressive program to improve energy-efficiency at existing schools.